Lewis was an early pioneer of abstract expressionist painting, driven to overcome the constraints of representation with works that reference bebop and jazz as well as the history of African art. Lewis was active in the Civil Rights movement and associated with and championed African American artists, such as Romare Bearden and Jacob Lawrence, but sought in his work to transcend racial boundaries. Lewis's delicate compositions sometimes appear suspended, as they unfurl in seemingly spontaneous gestures. Their linearity alludes to processions and might imply social movements as well as a range of emotions.